Abstract: Unauthorized distribution of data within a wireless communication system (101-102) can be detected by coupling a security gateway (103) between the wireless communication system (101-102) and a public data base system (104). When the public data base system (104) sends data to a requesting member of the wireless communication system (101-102), the data is intercepted by the security gateway (103). As the security gateway (103) is receiving the data, it is searching the data for a security tag. When a security tag is found, the security gateway (103) determines whether the security tag is assigned to the particular data base transmitting the data (105-106). If the security tag is not assigned to the particular data base, the security gateway identifies the particular data base as a potential unauthorized distributor of data (117).

Abstract: In a TDM wireless communication system (100), a central controller (104) monitors the transfer of a message (108) in order to determine a system grade of service. Based on the system grade of service, the central controller dynamically allocates a lesser or greater number of wireless communication resources (105). Alternatively, a communication unit (101) can directly request additional wireless communication resources.

Abstract: A communication unit (103) transmits a concurrent monitoring request to a base station (102). Responsive to the concurrent monitoring request, the base station provides multiple communications from at least one dispatch position (101) and at least one other communication unit (104) to the communication unit. Upon reception of the multiple communications, the communication unit simultaneously renders the multiple communications audible, allowing an operator of the communication unit to concurrently monitor the multiple communications.

Abstract: A frequency reference, a time reference and data may be provided on, and subsequently extracted from, a single information stream. To achieve this a modulator 102 generates the single information stream by modulating the data on the frequency reference and pre-empting the data modulation to modulate the time reference on the frequency reference. This single information stream is then provided on a single bus 106 which is coupled to a plurality of base stations 103-105. The base stations 103-105 each include a demodulator 107-109, which recovers the frequency reference 117, the time reference 118, and/or the data 116, from the single information stream.

Abstract: A communication unit's estimated time of arrival at a target site may be determined when the location and velocity of the units has been ascertained. From this information (119), along with terrain information, an estimated time of arrival at a target site may be calculated. Having calculated the estimated time of arrival, this information is then transported to the communication units (102, 103) which is subsequently displayed to their operators.

Abstract: A console (203), in communication with a zone controller (201) via a communication link (208), sends a communication request that includes an inbound time slot identification, an inbound audio switch identification, and an inbound multiplexer identification to the zone controller. In a first embodiment, it is assumed that the inbound time slot identification not only identifies an inbound time slot, but also a similarly identified outbound time slot as well. In a second embodiment, an outbound time slot identification is explicitly provided as part of the communication request. An outbound audio switch identification and an outbound multiplexer identification may also be provided as part of the communication request. In this manner, the need for the console to have access to all time slots is eliminated, and the complexity of the zone controller and the console can be reduced.

Abstract: A monitoring computer (115) monitors the communications occurring within at least one communication system for a unique communication unit identification (ID) code associated with a communication unit (105, 110). In a first embodiment, for each occurrence of the unit ID code, the monitoring computer determines a location of the communication unit affiliated with that unit ID code. When two or more instances of the unit ID code occur within a predetermined period of time at locations separated by more than a predetermined distance, the unit ID code is identified as a potentially duplicated unit ID code. In a second embodiment, a counter is incremented for each occurence of the unit ID code. If the counter exceeds a predetermined number within a predetermined period of time, the unit ID code is identified as a potentially duplicated unit ID code.

Abstract: In a receiver (100), an encrypted communication (104) is decrypted using a decryptor (101) and a key (107) to produce a decrypted communication (105). A comparator (103) compares decrypted symbol patterns in the decrypted communication against a set of predetermined symbol patterns (108). When the decrypted symbol patterns are distributed non-uniformly relative to the set of predetermined symbol patterns, the receiver is identified as a target of the encrypted communication.

Abstract: Unauthorized use of a communication unit 102 in a wireless communication system 100 may be prevented by determining the location of the communication unit 102 each time it transmits an affiliation request or a service request. Knowing the location of the communication unit 102, the controller 101 can determine whether the location of the unit fits within a historical location pattern for that unit. If the location does not fit within the pattern, the controller 101 can deny the request or send an indication to a system manager 110 asking the system manager 110 to decide what should be done with this unit.

Abstract: In a Radio Frequency (RF) communication system using Time Division Multiple Access (TDMA) having time slots of a common duration, a quantity of information bits to be transmitted is provided. Based at least in part on the number of information bits to be transmitted, a modulation technique is selected from a plurality of modulation techniques. Based at least in part on the modulation technique selected and the common duration of the time slots, the information bits are formatted into blocks, each block containing an equal number of information bits. The blocks are transmitted in the time slots such that a predetermined symbol rate is maintained.

Abstract: An uncorrectable set of input vectors (303), comprising a primary input vector (P) and a secondary set of input vectors (S), is provided at a sender (301). The secondary set of input vectors is error correction encoded and modulated with a predetermined input vector (PIV) to produce a secondary set of modulated vectors (S'). A predetermined codeword (PC) is sent along with the secondary set of modulated vectors to a target (302). At the target, the predetermined codeword is decoded and the resulting decoded predetermined codeword 306 is used to demodulate the secondary set of modulated vectors. As the predetermined codeword is chosen such that, when decoded, it is not identical to the predetermined input vector, the secondary set of demodulated vectors (S") will contain a sufficient number of errors to indicate to the target that the set of input vectors is uncorrectable.

Abstract: In a multi-site trunked communication system, a method for allowing a communication unit to place a unit directed group call consists of identifying, by the unit initiating the communication, a target unit and transmitting identification information of the target unit and a group call request to a communication resource allocator. Upon receipt of the identification information and the group call request, the communication resource allocator processes the request and when a resource is available in the site that the target unit is located in, allocates the resource such that the target unit and any other units of the communication group in the site can participate in the group call.

Abstract: In a receiver, a channel quality metric (220) is determined by demodulating a received second stream of discrete data elements (205) using a received first stream of discrete data elements (203) to produce a demodulated second stream of discrete data elements (212). The demodulated second stream is decoded, leading to an estimate of the second stream of discrete data elements (214). The estimate of the second stream is then re-encoded and the resulting re-encoded stream of discrete data elements (216) is compared with the demodulated second stream to produce the channel quality metric. Derived in this manner, the channel quality metric provides a method for detecting decoding errors in a stream of critical data elements.

Abstract: Signal sources provide frames (302-303) to a comparator (206). For each frame, codeword error statuses for each of the codewords and a frame error status (313-314) are determined. Codeword error statuses are provided for priority sets of codewords (306, 308) and are not provided for non-priority sets of codewords (311, 312). The codeword error statuses for members of the priority set of codewords for each frame are compared, wherein the members have substantially identical codeword identifications. Selected priority codewords are produced by selecting members of the priority sets having favorable codeword statuses. Furthermore, the frame error statuses for each frame are also compared. Selected non-priority codewords are produced by selecting the non-priority set of codewords corresponding to a favorable frame error status. The selected priority codewords and the selected non-priority codewords are then provided as the favorable signal representation (304).

Abstract: A speech coder and decoder methodology wherein pitch excitation and codebook excitation source energies are represented by parameters that are readily transmissible with minimal transmission capacity requirements. The parameters are the long term energy value, a short term correction factor which is applied to the long term energy value to match the short term energy, and proportionality factor(s) that specify the relative energy contribution of the excitation sources to the short term energy value.

Abstract: A surface-mountable crystal resonator (100) is provided in the following manner. A first predetermined electrode pattern (105) and a second predetermined electrode pattern (201) are formed on a first major surface (104) and a second major surface (200), respectively, of a piezoelectric crystal substrate (101). Additionally, a first predetermined attachment electrode pattern (106), electrically coupled to the second predetermined attachment electrode pattern, and a second predetermined attachment electrode pattern (202), electrically coupled to the first predetermined attachment electrode pattern, are formed on a first attachment area (102) and a second attachment area (103), respectively. The first and second attachment areas include extensions (107) that, when mounted, allow a conductive adhesive (301), placed on a mounting substrate (300), to flow and establish electrical connections with the first and second predetermined attachment electrode patterns.

Abstract: In a data transmitter (200), a precision timing signal receiver (201) provides a precise timing signal (203) to an informationally responsive comparator (205). The informationally responsive comparator compares an output (211) of a controllable oscillator (209) to the precise timing signal to produce a comparison metric. An output of the informationally responsive comparator, comprising a combination of an information signal (207) and the comparison metric, is then used to control the controllable oscillator.

Abstract: In communication system, multiple communication units are selected to receive a message via multiple broadcast units. A communication resource controller identifies a set of broadcast units needed to transmit the message, which are further identified as contending and non-contending broadcast units based on contention information. Identification of each of the contending broadcast units is stored and the non-contending broadcast units are allowed to simultaneously transmit the message. When contention for the contending broadcast units is alleviated, the contending broadcast units transmit the message.